| 摘要 |
A method and apparatus for performing a two-phase commit of a transaction is provided. The mechanisms described herein perform a two-phase commit in a manner that reduces the number of messages transmitted between a coordinating database system and the participating database systems, and the number of log flushes performed to complete a two-phase commit. Once the coordinating database system determines that all participating database systems participating in a database transaction are prepared to commit, the coordinating database system commits the transaction on the coordinating database system. Forget requests are then transmitted to each of the participating database systems. Rather than waiting to receive a forget acknowledgment and performing other forget processing operations, the coordinating database system delegates this work to a forget collector. A commit acknowledgement may be sent to a user by the coordinating database system prior to receiving the forgot acknowledgements, and the user may proceed as if the whole transaction is committed on all database systems. When a participating database system receives a forget request for a transaction, the participating database system commits the transaction by generating a commit record in its log. Rather than flushing the log to make the commit persistent, and performing other forget processing operations, the participating database system hands off this work to a forget collector.
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